1. Field of the Invention
The present invention relates to relay devices, wireless communications devices, network systems, program storage media, and control methods therefor, and more specifically relates to technology for security during wireless communications in network systems including relay devices and wireless communications devices.
2. Description of the Background Art
Conventionally, as part of network systems carrying out data communications, access points (relay devices) that connect wireless communications devices to a network to carry out wireless communications are used. In order to reduce the possibility of access by users who are not valid users and have no authentication (also referred to as “unauthorized access”), the access points determine whether to allow the connection before connecting the wireless communications devices to the network. Various methods are used for such determination. One example is a method (e.g., the WPA-PSK (Wi-Fi protected access-pre-shared key) or the WPA2-PSK) of using previously-registered shared keys between the access points and the wireless communications devices (see Japanese Laid-Open Patent Publication No. 2007-013348).
In this area, communications data transmitted/received between the access points and the wireless communications devices are easily intercepted. Therefore, it is preferable, in technology using the shared keys described above, to update the keys (avoid continuous use of the same key for a long time period) to reduce the possibility of unauthorized access. However, operations to update the keys between the access points and the wireless communications devices are burdensome to users. Particularly in recent years, users tend to use a multiple number of wireless communications devices (e.g., computers, video game devices, mobile phones, TVs, video recorders, and the like). In this case, updating keys for all the wireless communications devices is particularly burdensome to users. As a result, users do not update the keys, which risks impairing security.
Such problem is not limited to systems that use the above-mentioned WPA-PSKs or WPA2-PSKs, but is a problem common to systems that use previously configured data to determine whether to permit a connection.